


The Interdimentional Hypothesis

by LightningStorm03



Category: Undertale (Video Game)
Genre: Alternate Universe - Flowerfell (Undertale), Alternate Universe - Swapfell (Undertale), Alternate Universe - Underfell (Undertale), Alternate Universe - Underswap (Undertale), Multiverse, No Smut, X tale, its a slow begining but we briefly see a main character, just some happy feels, most of this is domestic fluff
Language: English
Status: In-Progress
Published: 2020-01-02
Updated: 2020-01-02
Packaged: 2021-02-27 07:28:10
Rating: Not Rated
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 4,116
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/22083382
Author URL: https://archiveofourown.org/users/LightningStorm03/pseuds/LightningStorm03
Summary: While typically it is a fairly unknown theory within day to day life, an assumption that alternate realities exist beside our own where some consist of only minute differences and others are barely recognisable. The idea of this can send others into an existential crisisDid they exist in that universe?If so, what am I like?Am I bad?Or am I better?If not… has anything changed?Or is your existance worth nothing?But you know all about that, don’t you? Perhaps… you know more that even them.
Relationships: Sans (Undertale)/Reader
Kudos: 4





	The Interdimentional Hypothesis

A soft breeze brushed past, small leaves fluttered past as they crossed your vision, bursts of colour occasionally lighting up the forest in front of you. The forest was thick, aside from the few trees out front while it faded quickly into an unrecognisable bush. A small opening quickly curved and turned inwards the forest, a path.

You continued forwards, without any hesitance, the faded and tattered scarf lying on your shoulder pulled upwards and a backpack pulled closer to the white dress shirt that you have on, the shirt puffed out and was cuffed at the elbows, tucked into a fake corset, a decorative part of the shirt that you had quickly grown attached to, small ornaments on the corset hid pockets and slots that held small charms or objects, right now it just held your phone and keys which were held together with a puff. Black high waisted jeans rested snugly on your hips and a pair of ankle tall scuffed boots on your feet

They crushed the small rocks beneath your heels as you continued on your journey down the covered path, your appearance was sudden, one minute you were at home, definitely not wearing the same ensemble you were now, relaxing when the doorbell had sounded. You shouldn’t have answered it, but you also didn’t know was about to happen, that there was but a black abyss in front of it.

You’d been done with adventure, the metaphorical bucket list completed over and over. you were getting older, yet you never seemed to die, as each year passed nothing allowed that final wish to come true. And that door that you’d opened seemed to set you on yet another path.

The cool wind tumbles past when you become focused on the world once again, you’d followed this path; the wisps of light, for days upon no end, stopping only to eat and sleep. Just like all other impromptu adventures before now you ignored the preamble and the side quests, you didn’t stop for anyone, you just wanted this to end, to go back home, to go back to your confined space where nothing was new.

Where nothing new could find you.

The feel of freedom, while not new to you, was not exactly something you liked, at least not in this world, your real home was a nice roof top with a small view, the mattress you’ve had for years on the floor with pillows galore but only one blanket, the walls were covered by paper, different ideas on each and the shelves littered with books, some completely empty but pretty to look at. It was your comfort.

But looking at the trees littering this forest set you in un familiar territory, whatever species they were they weren’t familiar, the leaves themselves gave off a great deal of warmth, too much to be a normal tree, they creaked but sounded liquid, they glowed more the further you walked.

It smelled of spice, mint and had a faint undertone of chocolate. It was weird, but not the weirdest you’d seen. Your mind began wandering to all those other worlds you have seen, the abstract constructions its creators or characters had managed to create were all individually creative. This world must be too, then.

But already you could see the abnormalities in this universe, there were too many outcomes that could happen and yet nothing split. no timelines were being created, no new loads being restarted in order to see the world repeat again and again and again.

You were tired of this never-ending game, resets, timelines, worlds that needed to be saved, what difference did this world have that needed you again. Was this merely another repeated scenario of someone greater in a land where fictional meet reality? Where the main character feel in love? Where the disaster found their soulmate?

Perhaps it was, perhaps in this timeline you were the main character…

You’d quickly shuffled that thought away, not once on your adventures did you manage to be that cursed, that wasn’t your job anyway. As a collector it wasn’t your job to become the hero nor become an active force for a player to become attached in order to complete the quest, they were usually your antagonist anyway.

It was your job stop the spread and overpopulation of timelines within your domain, to make sure there were no repeats, anomalies and glitched pathways to decaying universes. Following the path forwards, you sighed, ‘this looks to be a very long adventure that you can’t wait to finish.’

The further you’d walked the quieter it had begun to turn, the loud creaks of the trees swaying to stand still, the wind rocking to a steady movement as a town   
appeared.

\----------------

The town had been quiet, despite the ruckus the news had announced since the arrival of monsters, it was somehow peaceful. The quiet chirps of a brightly shining duckling and its mother that had just passed was refreshing, a bunny monster with blue fur rushing past with flowers had left a small smile on your face as your imagination sored. This world, this timeline was a remnant of an Undertale save. Undertale being a very popular videogame that judged the player and its actions. Refreshing wasn’t the only word you had for this world; you could even say you felt content with the reveal.

The moment you had left the forest clearing, a small figure had managed to rush past, they were to be but a blur if it were not for them tripping over their own feet. Monster kid, a character you’d instantly recognised from the game prompted you to help them to their feet. They didn’t stay long but thanked you with a quick “Cheers” before they disappeared again. But that only left more questions for you to go over as you trudged your way through the end of the forest and towards town, presumably the town resting at the bottom of Mt. Ebott.

Why were you here if this world was Undertale? The game had ended in an open solution; therefore, the possibilities of alternate timelines were possible and therefore didn’t need trimming or reduction. The multiverse surrounding this world had already been large and for another, this wasn’t a world under your control. So, you shouldn’t be here, it should have been one of the others, preferably the carer of this world. But still, you were brought here to do your job, or to at least do something. From what you could tell from a surface look of this world, monsters have been above ground for at least two years, long enough to establish full rights for monsters and construct housing for many.

But that didn’t help you with your own search, the lights that had led you towards the monster city had disappeared once MK appeared, so you trekked in an unknown direction. There was no more pull, no identifiable person to ask for your quest, no distinguishable motive for you. When you were brought to a new world, it would always be clear to you what you needed to do, and in most cases you’d always start at the beginning of the story and would have to follow the path of a player.  
But this was turning out to be a story that not even you could predict, or perhaps it’s a story that has been told before? Could you take advantage of this? Make your own life here? What were you doing here? Why are you here?

w̵̛ͅh̷̫́y̸̳͝ ̵̩̈́d̸͓̽o̸͉͑ ̸͉́ÿ̷̗́ǫ̶̂ṵ̸͌ ̶̲̿e̶̬̚x̴̥͘i̵̩͛s̶̙͐t̶̞̕ ̷̫̀ḥ̴e̴̼͘r̸̫͝e̷͍̽?̴͌ 

\----

“Order for a warm regular cappuccino, three sugars!”

You startled awake and quickly gathered you purse to walk up to the coffee counter to grab your drink, smiling at the barista before leaving the small café, the chimes on the door jingling to signify your leave. Taking a quick gulp, you strolled down the footpath with motivation, your life here so far hadn’t been bad, if anything it was calm, and somehow you’d managed to become quite fond of what you had found here. It wasn’t your hole in the wall, the room you’d called your home, but it was something. At least here you weren’t expected to do something, you didn’t need to ‘work’. No doubting it you’d missed home dearly, but this adventure had quickly swerved from an unknown fight for justice towards slice of life. 

You were taking advantage of this world, you knew that. By not doing your duty, by not helping whatever this world needed done but it had been so easy to escape that path, to create your own. Maybe this is why they had never given you domain of an open-ended world, they could easily lose you to freedom. And while that precaution was obviously taken, you’d had still managed to take it. This wasn’t selfish, you were still looking after the world, just not in the way they’d probably wanted.

The frisk of this world stuck true to the intention of the player. They were a child past the age of 10 but with the maturity of a young adult, their gender ambiguous and whenever they referred to by the spectrum they would purposely ignore them. Watching recaps of the ambassador on a podium getting asked questions was always funny, the larger reporters always slipping into titles and inappropriate questions only to be immediately shut down by Frisks family. The queen and king of monsters respectfully

The King and Queen are as typically described, large bi-pedal goat monsters with the elegance of pure-breed royalty, the only difference that could be seen within the recording were their outfits, the royal emblem was clearly visible but each were wearing clothes fitted with expensive silks, gold and gems. Both Toriel’s and Asgore’s horns were adorned with delicate but impressive crowns and had strings of crystals draped and hanging

The captain of the royal guard, Undyne. Was also there in the video as well as Alphys, the royal scientist. Papyrus, the Monster Mascot and official member of the royal guard and Sans, the assistant scientist and known judge of the underground.

It surprised you, that their positions did not affect their reception and integration into human society, that Sans position as judge had been so blatantly placed into the world, the others had been understandable. The formation of a monster police force was needed, and to have a monster mascot wasn’t to off the charts and neither was having a leading scientist. But to be announced so nonchalant to the human race that you were the ‘judge’ of the underground. 

That was not expected, at this your suspicions that the reason you were here was because of him. Of course, it would be him. The one other person who you could confirm has knowledge of timelines and universes aside from the player. But you couldn’t just barge into their lives and announce that you know their secrets, and besides they seemed to have everything in control, there would be no need for interference.

Looking to the sky you breathed out and stared with content at the park Infront of you, it was time for a nap.

\---

“Order for a warm regular cappuccino, three sugars!”

It has been 3 months since you’ve arrived in this multiverse, one since you’ve become a regular at this coffee shop. Gathering the cup of coffee and immediately leaving to walk down the street to the park, you still don’t have anywhere to live, you’ve been sleeping within the woods, on the top branches of tree in order to watch the sun fall and rise each day, wither way sleep did not find you often, god knows how you’ve survived this long on just a branch but life prevails. You wouldn’t consider yourself entirely homeless, you’ve been in a situation like this before, stuck in a city with no place to call home. So, you went around and went where you needed.

Tip number one if you ever find yourself on the streets, try to find a gym and sign up for a membership, they provide showers and some places even have cleaning supplies that you can use so you can be on top of your hygiene and it’ll also be somewhere you can stay during the day if the weather turns for the worst.

A loud shrill from beside you echoed quickly snapping you out of your mind, it was a flower, a flower with a very distinguishable face but…

“H-hey! Human!” there was no way this could be Flowey, he looked so, broken. His eyes darted side to side, and his yellow petals were dull and shaking.

“Look could you, uh help me? I-I think im lost and I don’t know whe- where I am and-and-“ he kept shrinking as if he was beginning to regret his decision, or was becoming uncomfortable under your gaze, this was weird. This was undoubtably new.

“I-I stars just Forget it! Ill find my-my way home myself” before he sunk below the ground you quickly kneeled and faced the monster, without even noticing you had already made your way back to your tree. The flower had flinched at your sudden movement as leaned backwards.

You let you face rest and a soft sigh tumbled from your lips, you hadn’t spoken much and that strain of speaking again was something of an annoyance but, you were going to help, it didn’t sound to taxing. Besides kindness can go a long way.

“Hey, sorry about my static silence, I didn’t expect anyone to be out here” you smiled down at him as you watched as his petals slowly stopped shaking and he unfurled from his petals

“Was there anywhere specific you needed to get back to? Home?” you’d asked, he brightened at the suggestion and nodded with vigour ‘he was very expressive’

“My home, its uh, on Dreemurr street, past the intersection near that Spiders bar, T-Truffles I believe!” he beams softly

You’d stopped for a moment, while you do know the directing towards Dreemurr street, the acknowledgement of a spider bar was what threw you, wasn’t it supposed to be a café? It was another anomaly that you could document later, right now you had a flower to take care of.

“C’mon” you murmured, gently laying your hand against the soil next to the flowers stem, hesitantly he shifted to grip your hand and slowly you stood straight and began to wander back into town, your coffee and flower in hand

“So, what’s your name, kid?”

“Just call me Fell, Fell the Flower”

\-----

There you were, with the moon already high in the sky and despite the two hour trip (Apparently Fell had gotten mixed up with an entirely different café called Firestarter which you swore you could see a very poppy fire elemental dance around within the windows but you ignored it, mostly to try and get Fell home at a reasonable time) but as you were about to knock the door cracked open, just as your knuckles touched the doors.

The smell of Chocolate and Butterscotch immediately scorched your nose, the scent was extremely strong and grew as a short figure popped their head out of the door, bright ruby red eyes stared out and directly at you, messy and curled strands of dark auburn hair filled your sight. Without a doubt you can instantly tell its Chara, the supposedly dead child of the king and queen.

You scrunched your face and let your eyes wander over their form, true to the game, they were dressed in green and yellow and was as pale as a piece of paper, but at the moment it seemed they had a thick pair of light blue overalls on top of their leggings that puffed out making it look like one of those cartoon ducks, nether the less they were very much older than Frisk, they appeared to be around 16, or at least roughly how old you looked like when you were ‘16’. And again, following the game, it made sense they were as ambiguous with their gender as well.

They frowned and gripped the door as you looked back at them, “W’dya want.”

You felt sweat starting to form as you carefully began to speak “Uh your friend here got lost, he said he lived here?” careful you lifted your arm to show the now sleeping flower, who’d wrapped himself tightly up your arm

Their eyes loosened at the sight of the flower and they quickly threw open the door and tugged at your hand, pulling you forwards with an unknown strength. You stumbled as they gripped your hand and brought it closer to them

“Flowey…” they whispered quietly, before a grin grew on their face and they turned back into the house shouting “Guy’s! Someone Found Fell!”

Before you could stop them they continued to drag you further into the house and as you tried to back up the door crashed close. Chara began to pull you through a wide corridor towards their dining room. The sudden movement, noise and smells slowly waking Fell in the process

The moment you entered the dining room you could instantly see multiple large presences in the room, and of course the presence of multiple players. You felt your soul drop as you noticed the characters in the room, multiple different Frisk’s and Chara’s, as well as Asgores, Toriels and Asriels. You internally began to choke, no   
wonder why you were called to this world, someone had definitely Fucked up big time. And you had a guess on who.

The first to stand at your presence was Frisk, the main one who also had a pair of overalls but darker to match their own outfit, you side glanced the Chara who’d tugged you along with a small simple smile, If you’d have to guess you can safely say that they’re from Underswap.

You awkwardly smiled and despite being much older than everyone in the room, finger gunned them and stuttered out a hello like the nerd you are.

Fell who was now awake and swaying as you did so, giggled (Which had completely thrown you off) and beamed at his family before him “L-look! I made a new friend!”

You hunched your shoulders “Uhm, hey, yeah look, he got lost near where I chill and asked for some help to get home sorry I couldn’t get here earlier, I don’t own a car or anything.”

Frisk then ran up to you and held out their palms to you, in which you’d instantly seceded and held Fell out to them, instantly Fell attached himself to them and relaxed into the crook of their neck to which Frisk giggled and shuffled off towards large and wide flower pot they had filling an entire wall.

Quickly taking in your surroundings you notice the entire wall with the flowerpot covered in different plants, and buttercup flowers painting the edges of the wall, you kept call as another Flower, which you can assume to be the original, pop out of the pot and sneer at Fell as Frisk planted him next to Flowey. The room was incredibly large, as it also connected to a lounge where many recliners were placed, yet were all occupied, and beanbags on the floor Infront of the couches, a curved and wide table with over 16 sets of chars sat near the right corner of the room with different flowers and small puzzles occupying the centre and many shelves that dotted the rest of the walls held numerous book, all looking well used and loved.

You sighed as you looked back up and focussed on who you guessed were the heads of the house hold, “Sorry for any inconveniences, but I should really start going I’ve got a fair way away to walk before I get back”

As soon as you finished Frisk rushed back to you and began waving their hands and shook their head and began leading you to their dining table, gesturing you to sit down, which you did after feeling another pair of hands push you to sit, looking upwards you see a baby faced goat, an Asriel alternate.

You then take time to look at everyone in the room, The original Toriel and Asgore were Standing in the doorway to what you assumed to be their kitchen, each holding plates of food, as they quickly rushed in and out with more, filling the table with an array of dishes. The Asriel next to you dressed in a dark blue jumpsuit and rainbow bandanna, was illuminated with happiness while a Chara at the other end of the table with a light green hoodie and plain white shirt below didn’t look too impressed with your appearance, but seemed relieved at the appearance of Fell, they appeared to be one of the older alternatives, the same going with Asriel and without a doubt at their outfit they were the StoryShift siblings. Their Asgore and Toriel counterparts currently missing from the currently gathered group, but obviously present if the photo frame behind both that held the family said anything.

On one of the beanbags was a Frisk, with a deep scar crossing the bridge of their nose and a button up cardigan in red and black that draped down towards a pair of short shorts and black leggings, their shirt entirely black apart from a logo spelling out ‘Stranger Things’, they appeared nearer to Chara’s age which was roughly 15. Underfell if you guessed correctly. Above them on a throne couch sat a large goat monster, an Asgore who in contrast to the original, had hair that was pitch black, his horns and fur scuffed, but despite the universe and sight he looked content as the Toriel besides him was curled in her corner looking you over with a pair of knitting needles in her paws.

Another frisk sitting just behind Underfell! Frisk looked timid, and was dressed in a long sleeved, off the shoulder, striped jumper and a pair of dark grey sweatpants, but spotted around their body, more particularly around their face were dozens of small buttercup flowers, as a Flowey alternate was also snuggled close in the crook of their neck. FlowerFell.

Another Chara and Frisk were nearer towards the couches, each had White and black hair respectfully and both dressed in a monochrome attire and despite the appearance of literal 12-year old’s, the two both held intense energy and power over the room, X-tale. The goat counterparts were not present.

Lastly a pair of Chara’s sat together on one of the couches, each looking more identical than the others, and also the youngest by appearance, neither looked older than 7 years, the only difference that can be clearly distinguished was the alternating colour pattern of their out fits and the soft, yet sentient Temmie plushies in their hands. Both from different Swapfell universes.

You felt as if you didn’t belong, not with this group at least. Toriel smiled at you as she brought in the last large dish from the kitchen, placing it down and offering you a hand. “thank so much my dear, for helping our dearest Fell home, please stay for dinner, I promise it’ll be good”

…perhaps you could stay a little while.

\---

“orda’ for the warm capp’, three suga’s”

You’d almost didn’t react, the new voice had startled you somewhat after hearing the same voice for the past 5 months, but you couldn’t predict it to be the same, you were awfully late today and you didn’t know whether or not Kid, your regular barista would be in at this time. The smooth baritone voice had knocked you sidewards though, until you saw the barista at the station.

It was a Sans, and under any other circumstances you would have believed him to be from Underfell if it wasn’t for the pulsating star shaped necklace dangling from the top of the pristine white dress shirt he currently had on, He was a Fell monster but not the one from Underfell, he was another monster from the FlowerFell clan.  
After your initial meeting with Frisk and their ‘siblings’ you learned that here the monsters were split into different clans and were said to come from different districts underground, so to make labelling easier for the human government, they became identifiable through clans. It had helped many humans distinguish which monsters they preferred, many avoided monsters in general anyway but avoided those from ‘hostile’ clans even more. 

Standing without pause and grabbing the drink, you took a sip then smiled at the Sans in front of you before walking off back towards the woods.


End file.
